1. Field of the Invention
The present invention relates to an image processing apparatus and method generating a binary image by processing a multilevel image.
2. Description of the Related Art
For conventional paper form recognition, strokes of handwritten characters, etc. are extracted from a grayscale image of an input paper form, and a recognition process is performed for the characters. A stroke corresponds to part of a pattern structuring a character or a ruled line, and is represented as a line pattern.
If a plurality of types of strokes such as a handwritten character, a ruled line, etc. coexist and contact within an input image, the differences among the strokes are distinguished based on the graylevels of pixels, and a stroke desired to be separated (a target stroke) is extracted.
However, if the graylevels of strokes of different types are almost the same, these strokes cannot be properly separated only with their graylevels. Furthermore, since the graylevels of pixels vary in an outline region corresponding to the boundary between a stroke and a background, a target stroke cannot be correctly detected even if the graylevels of strokes of different types are distinct.